US 4,109,447 AGranted

Mower of the cross-flow blower type with blades of opposite helix angle

OwnerHugo S. Fergusoninventor

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Abstract

In a mower of the cross-flow blower type the rotor of the blower has a plurality of sections with predetermined blades of at least two adjacent sections of opposite helix angle and having cutting edges which overlap in the axial direction and are angularly spaced about the rotor axis in the overlap region, thereby producing counteracting axial components of air velocity. Preferably at least one blade in each section is shorter than the rotor length and advantgeously all blades in a section are shorter, with ends angularly spaced from and overlapping the ends of the blades of adjacent sections. Preferably each section has blades of opposite helix angle to produce counteracting components of air velocity in each section. Advantgeously each section of the rotor is formed of an integral sheet bent to form end supports and a pair of blades of opposite helix angle. The blades are preferably of the hook type with the leading edges of the hooks serrated. Marked reduction in blower noise can be attained, with good mower performance.

Claims15

Dependent claims

A mower of the cross-flow blower type comprising

(a) a carriage,
(b) a cylindrical rotor mounted on said carriage with the axis thereof substantially horizontal and extending laterally of the carriage,
(c) said rotor having a plurality of sections along the axis thereof with a plurality of circumferentially-spaced approximately helical fixed blades in each section moving in the same path of travel and spaced from the rotor axis to leave the major portion of the interior of the rotor free for air flow through the rotor transversely thereof,
(d) motor means for driving said rotor in a rotational direction such that the lower blades move in the normally forward direction of travel of the mower,
(e) the outer leading edges of the blades being sharp to form cutting edges,
(f) predetermined blades of at least two adjacent sections being of opposite helix angle and having cutting edges which overlap in the axial direction and are angularly spaced about the rotor axis in the overlap region thereof,
(g) the cross-section of said blades having at least a portion on the leading side thereof which slopes backwardly and inwardly with respect to the direction of rotation of the rotor,
(h) and a blower conduit cooperating with said rotor to form therewith a cross-flow blower,
(i) said conduit comprising upper and lower wall sections extending laterally along the length of the rotor and having respective portions close to the rotor at circumferentially spaced positions separating inlet and outlet regions of the blower,
(j) said inlet region opening downwardly and forwardly with a portion of the rotor therein exposed to material to be mowed,
(k) the portions of the mower adjacent the rotor being non-shearingly spaced from the path of travel of said blades.

8 more elements

A mower of the cross-flow blower type comprising

(a) a carriage,
(b) a cylindrical rotor mounted on said carriage with the axis thereof substantially horizontal and extending laterally of the carriage,
(c) said rotor having a plurality of sections along the axis thereof with a plurality of circumferentially-spaced approximately helical fixed blades in each section moving in the same path of travel and spaced from the rotor axis to leave the major portion of the interior of the rotor free for air flow through the rotor transversely thereof,
(d) motor means for driving said rotor in a rotational direction such that the lower blades move in the normally forward direction of travel of the mower,
(e) the outer leading edges of the blades being sharp to form cutting edges,
(f) the cross-section of said blades having at least a portion on the leading side thereof which slopes backwardly and inwardly with respect to the direction of rotation of the rotor,
(g) each of said sections of the rotor having at least two blades of opposite helix angle relative to each other with the ends of the blades in one section angularly spaced from and overlapping the ends of the blades of adjacent sections,
(h) and a blower conduit cooperating with said rotor to form therewith a cross-flow blower,
(i) said conduit comprising upper and lower wall sections extending laterally along the length of the rotor and having respective portions close to the rotor at circumferentially spaced positions separating inlet and outlet regions of the blower,
(j) said inlet region opening downward and forwardly with a portion of the rotor therein exposed to material to be mowed,
(k) the portions of the mower adjacent the rotor being non-shearingly spaced from the path of travel of said blades.

8 more elements

Dependencies are inferred from the claim text.